uberfetch

A thin layer over fetch which makes JSON the default, and turns HTTP errors into Promise rejections.

import uberfetch from 'uberfetch';

get JSON

uberfetch('/cats/10')
  .then(res => /* do stuff */);

which is equivalent to:

function rejectOnRequestError(res) {
  if (res.ok) return res;
  return Promise.reject(new RequestError(res));
}

fetch('/cats/10', {
  credentials: 'same-origin',
  headers: {
    'accept': 'application/json'
  }
})
  .then(rejectOnRequestError)
  .then(res => /* do stuff */);

post JSON

let updatedCat = {id: 10, name: 'Keith'};

uberfetch.post('/cats/10', {body: updatedCat});

which is equivalent to:

let updatedCat = {id: 10, name: 'Keith'};

fetch('/cats/10', {
  method: 'post',
  body: JSON.stringify(updatedCat),
  credentials: 'same-origin',
  headers: {
    'content-type': 'application/json'
    'accept': 'application/json'
  }
})
  .then(rejectOnRequestError);

get HTML

// get some html
uberfetch('/cats/10', {accept: 'html'})
  .then(res => /* do stuff */);

which is equivalent to:

fetch('/cats/10', {
  credentials: 'same-origin',
  headers: {
    'accept': 'text/html'
  }
})
  .then(rejectOnRequestError)
  .then(res => /* do stuff */);

catch typed errors

let cat = {id: 10, name: 'Keith'};

uberfetch.post('/cats/10', {body: cat})
  .then(res => res.json())
  .then(body => FlashMessage.show(`${body.name} saved`))
  .catch(err => {
    if (err instanceof uberfetch.RequestError) {
      if (err.status == 422) {
        return err.response.json()
          .then(body => 
            AlertModal.show(`Validation failed: ${body.validationErrors}`)
          );
      }
    }
    return Promise.reject(err);
  });

Or with ES7 async/await

async function() {
  let cat = {id: 10, name: 'Keith'};

  try {
    let response = await uberfetch.post('/cats/10', {body: cat})
    let body = await response.json();
    FlashMessage.show(`${body.name} saved`);
  } catch (err) {
    if (err instanceof uberfetch.RequestError) {
      if (err.status == 422) {
        let body = err.response.json()
        AlertModal.show(`Validation failed: ${body.validationErrors}`);
        return;
      }
    }
    return Promise.reject(err);
  }
}

API

Use uberfetch(url, opts) exactly as you would fetch(url, opts), with the following additional opts which can be provided in the opts object:

• accept: string shorthand for setting an accept header, which takes either a mime type, or a convenient short name like form, html, text etc.
• contentType: string shorthand for setting an content-type header, which takes either a mime type, or a convenient short name like form, html, text etc.
• body: any works like the normal fetch body field, except that known content-types will be automatically serialized. When body is present, the default http method becomes POST.

In addition to the uberfetch() function, the following convenience helpers are available:

• uberfetch.get() automatically sets method: 'get'
• uberfetch.post() automatically sets method: 'post'
• uberfetch.put() automatically sets method: 'put'
• uberfetch.patch() automatically sets method: 'patch'
• uberfetch.delete() automatically sets method: 'delete'